<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
    <button onclick="alert('行内式')">点击</button>

    <script>
        var num = 10;
        alert('内嵌式');
    </script>
</body>
<script src="js/demo.js"></script>
</html>